Hematoma in the Retzius space after a cesarean section is a rare complication. The Retzius space, also referred to as the prevesical or retropubic space, represents an extraperitoneal artificial cavity situated between the pubic symphysis and the bladder. In instances where conservative treatment involving vigilant monitoring along with analgesics and antibiotics or ultrasound-guided percutaneous puncture proves unsuccessful, re-operation becomes imperative. Our case report concerns a second-parity pregnant patient who underwent a cesarean section in the 39th gestational week. A decrease in hemoglobin level on the third postoperative day, combined with the onset of febrile infection, an increase in inflammatory markers, and the manifestation of lower abdominal pain, prompted a thorough investigation of the puerperant. Imaging revealed the existence of a hematoma in the Retzius space associated with a mild blood coagulation disorder. Subsequently, the unsuccessful outcome of the ultrasound-guided percutaneous puncture of the hematoma, combined with the persistence of clinico-laboratory findings, led to the decision to perform a re-laparotomy on the 10th postoperative day after the cesarean section. During the surgery, a large hematoma was identified in the Retzius space, extending below the rectus abdominis muscles. The procedure involved surgical drainage of the hematoma, meticulous hemostasis, and the placement of negative pressure drainage in the Retzius space. The patient was discharged from the clinic on the fifth postoperative day after re-operation. Ten days later, both blood tests and ultrasounds were without abnormal findings. In this paper, following the case presentation, a brief review is provided regarding the diagnostic and therapeutic approach of patients with hematoma in the Retzius space after cesarean section.